Research

Current Projects

The continental crust and the volatile cycle – The global carbon cycle plays an important role in the long term self-regulation of the Earth system. However, the complex interaction between its deep, solid Earth component (i.e. crust and mantle), Earth’s fluid envelope (i.e. atmosphere and hydrosphere) and plate tectonic processes is a subject of ongoing debate. Throughout Earth’s history, outgassing through volcanic regions may have largely exceeded carbon removal by burial and subduction into the mantle, yet the long-term geological records show that Earth has not experienced run-away carbonation of the atmosphere. An important carbon sink that is not yet adequately accounted for is the deep continental crust. My research indicates that the fluctuation in orogenic activity throughout the Wilson cycle has a critical role in achieving balance in the long-term carbon cycle during the Phanerozoic. 

Collaborators: Marie Edmonds (Cambridge), Brendan Dyck (Vancouver), Silvio Ferrero (Potsdam), Alessia Borghini (Potsdam)

Crustal growth and secular changes – Plate tectonics is the surface expression of Earth’s internal geochemical and geophysical evolution, but its origin and how it evolved towards its modern style remain highly debated questions. In modern convergent settings, the coexistence of subduction and back-arc related metamorphism represents a hallmark of present-day tectonic processes. The gradual increase in the abundance of paired metamorphic belts in the geological record since the Paleoproterozoic indicates Earth’s progressive shift towards a generalized plate tectonic regime. Although such evolution has been argued to reflect the secular cooling of the mantle, there is a lack of detailed information concerning the metamorphic evolution of each supercontinent cycle taken separately. Similarities and/or differences between these cycles are keys to decipher the linear or episodic nature of plate tectonic processes.

Collaborators: Hugo Moreira (Montpellier), Mathias Schannor (Cambridge), Brendan Dyck (Vancouver)

Partial melting in the central Adirondaks, NY (US) – The mafic meta-igneous rocks of the central Adirondacks, a Mesoproterozoic outlier of the Grenvillian orogeny, are well known examples of lower crustal rocks metamorphosed to amphibolite and granulite facies during continent-continent collision. We investigate fluid flux and the occurrence and nature of polymorph-bearing nanogranitoids and partially glassy inclusions of throndhjemitic composition in garnet. Our work provides natural constraints for the water-present gabbro melting, but also contributes to the ongoing reappraisal of the metamorphic history of the Adirondacks. 

Collaborators: Silvio Ferrero (Potsdam), Robert Darling (NY), Chris Yakymchuk (Waterloo, Alessia Borghini (Potsdam), Felix Kaufmann (Berlin) https://www.uni-potsdam.de/en/geo/research/petrology

Convection in magmatic intrusions, Scotland (UK) – Accumulations of crystal cargo on the floors of sills record the strength of magma convection during crystal settling. While fining-upwards sequences can be interrogated to discern whether the crystals settled from static or convecting magma, some accumulations coarsen upwards:. Such coarsening upwards can only occur if the crystals grew as suspended grains in a convecting magma. I am exploring the extent to which magma convected using a detailed grain size examination of olivine-phyric sills on the Isle of Skye, together with analogue experiments. 

Collaborators: Marian Holness (Cambridge), Zoja Vukmanovic (Cambridge), Jerome Neufeld (Cambridge), John Maclennan (Cambridge)

Metamorphic Precambrian Terrains – Reevaulating the P-T-t-d paths followed by supracrustal lithologies in Precambrian convergent settings. This includes work on the Isua Belt, Greenland (3.7 Ga); the Unttental Plateau, Greenland (2.8-3.0 Ga); the Limpopo Belt, South Africa (2.7-2.8 Ga).

Collaborators: Claire Nichols (Oxford), Mathias Schannor (Cambridge), Jean-Francois Moyen (St-Etienne), Adrien Vézinet (Grenoble), Gary Stevens (Stellenbosch), Cris Lana (Ouro Preto)

Publications

In review

Nicoli, G., Ferrero, S., Darling, R., Yakymchuk, C., Wannhoff, I., & Gresky, K.  An ultrahigh temperature (UHT) metamorphic core in the Adirondack Mountains, NY. Journal of Metamorphic Geology (Geosphere).

In peer reviewed journals

2024

Brown, J. R., Buisman, I., Melendez, M. P. C., Dikaung, J., Steenssens, L. D., Edmonds, M., … & Mcc, B. (2024). Petrographic and geochemical evidence for a complex magmatic plumbing system beneath Bagana volcano, Papua New Guinea (accepted).

2023

Borghini, A., Nicoli, G., Ferrero, S., O’brien, P. J., Laurent, O., Remusat, L., … & Milani, S. (2023). The role of continental subduction in mantle metasomatism and carbon recycling revealed by melt inclusions in UHP eclogites. Science Advances, 9(6), eabp9482.

Nicoli, G., Mukherjee, S., van Schijndel, V., & Stevens, G. (2023). Duration of partial melting in the lower crust of the Limpopo collisional belt. Terra Nova.es.2022.106657).

Ferrero, S., Borghini, A., Remusat, L., Nicoli, G., Wunder, B., & Braga, R. (2023). H 2 O and Cl in deep crustal melts: the message of melt inclusions in metamorphic rocks. European Journal of Mineralogy, 35(6), 1031-1049.

2022

Holness, M. B., Nicoli, G., Rust, A., & Neufeld, J. (2022). The microstructural record of convection in the Little Minch Sill Complex, Scotland. Journal of Petrology, 63(11), egac106.

Mukherjee, S., Adhikari, A., Nicoli, G., & Vadlamani, R. (2022). Neoarchean (~2.73-2.70 Ga) accretionary history of the eastern Dharwar Craton, India: Lu-Hf and Sm-Nd garnet geochronologic constraints from the Karimnagar granulite-facies supracrustal enclaves. Precambrian Research (10.1016/j.precamres.2022.106657)

Nicoli, G., Gresky, K., & Ferrero, S. (2022). Mesoarchean melt and fluid inclusions in garnet from the Kangerlussuaq basement, Southeast Greenland. Mineralogia, 53(1), 1-9.

Nicoli, G., Borghini, A. & Ferrero., S (2022) the carbon budget of crustal reworking during continental collision: clues from nanorocks and fluid inclusions. Chemical Geology. https://doi.org/10.1016/j.chemgeo.2022.121025

2021

Schannor M., Lana, C., Nicoli, G., and Gerdes, A. (2021) Integrating in situ garnet U-Pb dating with thermodynamic modelling of metapelites in the Araçuaí orogen (SE Brazil). Journal of Metamorphic Geology.

Nicoli, G. and Ferrero, S. (2021) Nanorocks, volatiles and plate tectonics. Geoscience Frontiers. GSF-D-20-00769R1

2020

Nicoli, G. Water flux and partial melting in an Archean continental crustal column: example from the Dharwar craton, India (2020) Archean Granitoids of India: Windows into Early Earth Tectonics, Geological Society London Special Volume. 489, SP489-2018-88

2019

Nicoli, G. and Matthews, S. (2019). The Hebridean Igneous Province plumbing system: A phase equilibria perspective. Lithos, 348, 105194.

2018

Nicoli, G., Holness, M.B., Neufeld, J. and Farr, R. (2018) Microstructural evidence for crystallization regimes in mafic intrusions: a case study from the Little Minch Sill Complex, Scotland, Contributions to Mineralogy and Petrology. 173(12), 1-15

Nicoli, G. and Dyck, B, J. (2018) Exploring the metamorphic consequences of secular change in the siliciclastic composition of continental margins. Geoscience Frontiers, Special Issue: Secular Change in Earth Processes: Shifting Uniformitarianism, 4, 967-975

Nicoli, G., Thomassot, E., Schannor, M., Vézinet, A. and Jovovic, I, (2018). Constraining a Precambrian Wilson Cycle lifespan: an example from the ca. 1.8 Ga Nagssugtoqidian Orogen, Southeastern Greenland, Lithos, 296-299, 1-16

Vézinet, A., Moyen J-F., Stevens, G., Nicoli, G., Laurent, O., Couzinié, S. and Frei., D. (2018) A record of 0.5 Ga of evolution of the continental crust along the northern edge of the Kaapvaal Craton, South Africa: Consequences for the understanding of Archean geodynamic processes. Precambrian Research, 305, 310-326.

2017

Nicoli, G., Stevens, G., Moyen, J-F., Vézinet, A. and Mayne, M., (2017). Insights into the complexity of crustal differentiation from K2O poor leucosomes within metapelitic migmatites: Southern Marginal Zone of the Limpopo. Belt, South Africa. Journal of Metamorphic Geology, 35, 999-1022.

2016

Nicoli, G., Moyen, J-F, and Stevens, G. (2016) Diversity of burial rates in convergent settings decreased as Earth aged. Scientific Reports, 6, 26359.

2015

Nicoli, G., Stevens G., Moyen J–F. and Frei D., (2015). Rapid evolution from sediment to anatectic granulite in an Archean continental collision zone: The example of the Bandelierkop Formation metapelites, South Marginal Zone, Limpopo Belt, South Africa. Journal of Metamorphic Geology, 33, 177-202.

2014

Laurent O., Nicoli, G., Zeh A., Stevens G., Moyen J–F. and Vezinet A. (2014). Comment on Ultrahigh-temperature granulites and magnesian charnockites: evidence for the Neoarchean accretion along the northern margin of the Kaapvaal craton by Rajesh et al. Precambrian Research, 255, 455-458.

Nicoli, G., Stevens G., Buick I.S., and Moyen J–F., (2014). Comment on Ultrahigh temperature metamorphism from an unusual corundum + orthopyroxene intergrowth bearing Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa. Contribution to Mineralogy and Petrology, 167, 1022.

Taylor J., Nicoli, G., Stevens G., Frei D. and Moyen J–F. (2014). The processes that control leucosome compositions in metasedimentary granulites: Perspectives from the Limpopo Belt (South Africa) South Marginal Zone anatectites. Journal of Metamorphic Geology, 32, 713-742.

Selected conference abstracts

Nicoli, G., et al. (May 2022). Multiple partial melts trapped in garnets from the Adirondacks lower crust: clues for TTG formation. EGU22-2271 (talk).

Ferrero, S., Nicoli, G., et al. (May 2022). Mesoarchean nanogranitoids and fluid inclusions in garnet from migmatites of the Kangerlussuaq basement, Southeast Greenland. EGU22-4099.

Borghini, A., Nicoli, G., et al. (May 2022). Deep subduction of continental crust contributes to mantle metasomatism and deep carbon cycle. EGU22-5782.

Nicoli, G., Moreira, H., & Schannor, M. (2021) Earth’s metamorphic signal, supercontinent cycle and plate tectonics, RIP MSG 2021 (talk).

Nicoli, G., Dyck, B., Edmonds, M., & Ferrero, S. (2021). Crustal reworking and the carbon cycle. Goldschmidt2021(Virtual) 4-9 July (talk).

Nicoli, G, Neufeld, J. and Holness, M., (2020) The Moon in the Skye: Insights into the formation and evolution of the lunar magma ocean. EGU 2020 (poster).

Nicoli, G and Dyck, B. (2019) Deep crustal CO2 budget controlled by metamorphic reactions. Janet Watson Meeting 2019: From core to atmosphere: Deep carbon (poster).

Nicoli, G. and Dyck, B. (2018) Water redistribution in the continental crust. Granulites & Granulites 2018, Ullapool Scotland (poster)

Nicoli G., Holness, M., Neufeld, J. and Farr, R. (2018) Decoding magmatic intrusion crystallization mechanisms: a microstructural study from the Little Minch Sill Complex, Scotland. EGU 2018 (talk).

Nicoli, G. and Dyck, B. (2018) Secular changes in sedimentary source compositions and consequences for partial melting in orogenic beltsEGU 2018 (talk).

Nicoli, G., Garcia-Arias, M., and Dyck, B., J. (2017). Modelling crustal differentiation: A thermodynamic approach. AGU 2017 (invited talk)

Nicoli, G., Holness, M., Neufeld, J., & Farr, R. (2017) Microstructural indicators of convection: insights from the little Minch Sill Complex, Scotland. EGU 2017 (poster).

Nicoli, G., Moyen, J-F. & Stevens, G. (2016) Today’s Earth plate tectonics : the result of a 4.0 Ga long selection process. Workshop ETH: Origin and Evolution of plate tectonics, Monte Veritá, Suisse (poster).

Nicoli, G., Stevens G. & Moyen J-F. (2015) Burial rate in continental collision zone: a 3.2 Gyrs old history of orogenic diversity. Granulites & Granulites 2015, Windhoek, Namibia (talk).

Nicoli, G., Vezinet A., Moyen J-F., Stevens G. and Laurent O. (2014) 2.7 Ga heating event and P-T-t evolution of the southern marginal belt of the Limpopo belt, south Africa : consequences for neoarchean continental accretion. RST 2014, Pau, France (talk).

Nicoli, G., Stevens, G., Moyen, J-F. & Taylor, J. (2013) Leucosome formation by desequilibrium melting and melt loss: perspectives from the South Marginal Zone (SMZ) of the Limpopo Belt, South Africa. Goldschmitd 2013, Florence, Italy (talk).